Hello Subrata,

Your question is a bit confusing.

But let me clear that authorities have changed the pattern this year where there are two papers for JEE MAINS and after qualifying them you will be eligible for giving JEE Advance.

Getting good marks or percentile im JEE Mains will give you some good NITs while if you will qualify JEE Advance with good marks, you will be able to get the best IITs in India.

Good luck.